Weddings are typically happy occasions, but one in Illinois turned deadly when a man gunned down his daughter-in-law because he was upset she was about to divorce his son, cops say.

Officers with the Village of Schaumburg, a Chicago suburb, responded around 10:15 p.m. Friday to the Marriott on North Martingale Road where they located a gunshot victim in the parking lot, the agency said in a press release. She was suffering from a bullet wound to the head, cops said. Paramedics rushed her to the hospital, where she died.

Cops found that a citizen had subdued the alleged shooter, identified as 76-year-old Roland Schmidt; they also collected the gun. Detectives determined Schmidt was at a wedding held at the hotel along with his daughter-in-law, 45-year-old Christine Moyer of Ohio. As Moyer was leaving the event, cops say Schmidt followed her outside and shot her in the head.

“Through the investigation, it was discovered Schmidt was upset with Moyer over divorce paperwork which was filed against his son,” cops report.

Schmidt, of Stillman Valley, which is some 13 miles southwest of Rockford, is now facing a first-degree murder charge, cops say. Cops took him to the Cook County Jail. He”s set to face a judge on Monday.

Flory Sommers had just walked inside the hotel with her friends when the shooting occurred.

“I was inside by the ATM and I heard some people calling ‘gunshot!’ and then the manager said ‘was there a gunshot,’ and he said he was calling the ambulance, and then I just saw people move quickly to the elevator to the lobby,” Sommers told local Fox affiliate WFLD.